This invention relates to a system for evaluating the physical characteristics of animals and more particularly to a structured light system for three-dimensional measuring. Even more particularly, the invention relates to projecting structured light toward an animal or carcass, measuring the reflection of the light from the animal or carcass, and using the measured light to develop a three-dimensional surface scan that can be used to measure both the linear, volume and angular related characteristics of the animal and provide rapid, consecutive images of an animal in motion.
Throughout the history of the domestic livestock industry, mankind has attempted to measure animals, whether the need was to be taller, longer, thicker, leaner, wider or stronger, taking accurate measurements quickly has always been important. In modern times it has become more and more important to measure offspring of sires and compare those groups of offspring with like kind. Obviously, the sires that provide improved offsprings are in great demand and can provide the most improvement to a breed. Much of the future genetic progress will be attributed to our ability to improve the speed and accuracy of measuring animals.
Systems have evolved from measuring horses by using the approximate width of a hand; for example, a horse could be reported as 14 hands high which was about 56 inches. Currently some animals are measured at 15 different conformation points, however, most often the measurements are only visual appraisals, with even a tape measure being seldom used. Thus, there is tremendous need for more information and the improved accuracy of that information to accelerate breed progress.
One method of compiling data is shown in U.S. Pat. No. 4,745,472 issued May 17, 1988 to Hayes, entitled xe2x80x9cAnimal Measuring Systemxe2x80x9d. This method uses a video camera to take a picture of the animal, and then the picture is processed by a computer system to determine the measurements. Plastic patches were placed on several points of the animal, and measurements were made of these points. Another method of compiling data is shown in U.S. Pat. No. 5,483,441 issued Jan. 9, 1996 to Scofield, entitled xe2x80x9cSystem for Evaluation Through Image Acquisitionxe2x80x9d and U.S. Pat. No. 5,576,949 issued Nov. 19, 1996 to Scofield and Engelstad, also entitled xe2x80x9cSystem for Evaluation Through Image Acquisitionxe2x80x9d. These systems use a conventional video camera, so they can only measure in two dimensions. Thus, in addition to the camera measurement, additional hand measurements usually need to be made, or the data from several cameras must be coordinated. Coordination of the data from several cameras is a difficult task, requiring manual interpretation by a skilled operator.
An additional method for compiling animal conformation is shown in U.S. Pat. No. 5,673,647 issued Oct. 7, 1997 to Pratt, entitled xe2x80x9cCattle Management Method and System.xe2x80x9d This method, in part, explains the measuring of external animal dimensions. This method also measures using only two dimensions.
A three dimensional measuring system is shown in U.S. Pat. No. 5,412,420 issued May 2, 1995 to Ellis, entitled xe2x80x9cThree-Dimensional Phenotypic Measuring System for Animals.xe2x80x9d This system uses laser light signals to provide a three-dimensional measuring of linear and volumetric conformation traits of an animal, comparing those traits to predetermined traits and providing a rating of the animal. This system requires that the animal remain still during the laser scan of the animal.
It is thus apparent that there is a need in the art for an improved system which measures physical characteristics of an animal. There is further need in the art for such a system to measure in three dimensions. Another need is for such a system that does not require that patches be affixed to the animal before measuring. A still further need is for such a system that can measure in three dimensions using a single camera to provide linear, volume and angular measurements as well as improving the speed of imaging the animal. There is a further need for such a system that can provide rapid and consecutive three-dimensional images of an animal in motion. The present invention meets these and other needs in the art.
It is an aspect of the invention to measure physical characteristics of a live animal or carcass.
It is another aspect of the invention to measure the physical characteristics using reflected structured light.
Still another aspect is to measure the physical characteristics in three dimensions from a single camera.
Yet another aspect is to take rapid consecutive three-dimensional images of a moving animal.
Accurate three-dimensional information can be collected from a single location using reflected structured light. A three dimensional image is created by projecting a structured light pattern, for example wherein each element of the pattern is a circle of light and the circles are arranged in a grid pattern, a horizontal band or a vertical band of light, onto the animal and measuring the reflection of the elements of the pattern. The structured light from the animal is measured for differing distances by comparing the dimensions of the reflected structure light pattern elements on the animals to a known constant.
The pattern of circles is used to measure a predetermined number of locations on the animal, and the distance to each of these locations, thus creating a three-dimensional image of the animal. The radius of curvature of each of the circles can also be determined by the shape of each of the reflected circles. For example, an ellipse with an elongated vertical dimension indicates that the surface at the point of the ellipse is curving either away from the light source or toward the light source, and the length of the vertical dimension is used to determine the radius of curvature. The distance from the camera to the animal for multiple spots in the same vertical line indicates the direction of the curve, that is, whether the curve is concave or convex. This same concept is also used for horizontal patterns of circles to determine the radius of curvature in the horizontal direction, as well as whether the curve is concave or convex.
Because animals are symmetric, an image need only be taken of one side of the animal. Thus a single camera at a single location provides all the three-dimensional information necessary for conformation of an animal. With some breeds, such as dairy cows, it may be necessary to use a second camera or take a second image of hidden areas; for example, a dairy cow may need a second image of the mammary system as viewed from the rear to provide additional accuracy for that portion of the animal.
A computer system selects the points of the animal desired for the conformation, measures the distance between these points to provide the conformation data, combines the selected conformation data for each animal with an identification number, and stores the conformation data and number for each animal. In addition, an image of the animal, showing the markings of the animal, may be stored along with the other conformation data.